The present invention relates to an apparatus for volatilizing a liquid through blending it with heated gas.
The manufacture of packing containers for products with long keeping quality, such as sterilized juices or the like takes place in packaging machines of the aseptic type. In the packaging machine a material web or material blanks are converted to packing containers which are filled with sterile contents and sealed. The manufacture has to take place under aseptic conditions and the packaging machine thus must be sterilized internally before production commences. This is done preferably by blending a liquid sterilizing agent with hot sterile air so that a gas saturated with sterilizing agent of a suitable temperature and dew point is obtained. As the gas is conducted around the inside of the packaging machine, the sterilizing agent condenses on the relatively cool parts of the machine that come into contact with the gas. As a result a thin, uniform layer of sterilizng agent is formed which sterilizes the surfaces with which the contents or the packing material later will come into contact. Before beginning operation of the packaging machine, the sterilizing agent is removed by hot air which is conducted around the machine so that the sterilizing agent is evaporated again and can be discharged together with the air. In this manner the inside of the machine is sterilized and the production of aseptic packages can commence.
The sterilization method described has been found to work well in practice when the dew point of the gas mixture lies sufficiently high in relation to the temperature of the machine parts to be sterilized. However, if the machine parts to be sterilized are at too high a temperature at the start of the presterilization, condensation will not take place on the surfaces of the parts and the sterilization consequently will be incomplete. This will happen, for example in machines which are located in abnormally warm localities and in regions with a warm climate. The mixture of sterilizing agent and air which has been used up to now was produced through injection of liquid sterilizing agent into a pipe through which passed a flow of hot sterile air. The maximum dew point of the mixture obtained in this manner is 30-40.degree. C. which in certain cases proves to be insufficient. It has not been possible up to now to obtain by means of the prior art a higher dew point with the large flows which are necessary for the production of sufficient gas quantities.
It is an object of the present invention to provide a method for volatilizing a liquid through blending with heated gas, this method not being subject to the disadvantages of earlier methods.
It is a further object of the present invention to provide a method which makes it possible to volatilize a liquid in a gas and thus produce a mixture of a higher dew point and greater volume per unit of time than had been possible by means of known methods.
It is a further object of the present invention to provide a method for volatilizing a liquid sterilizing agent in hot air, this method being suitable for application in the presterilization of packaging machines of the aseptic type.
These and other objects have been achieved by a method for volatilizing a liquid through blending it with heated gas that is introduced into a chamber where a circulating movement is imparted to it at the same time as the liquid is introduced in the form of drops into the center of the circulating movement.
The method in accordance with the invention makes possible a rapid and complete blending and volatilization of the liquid in the hot gas. As a result, a mixture of a dew point of over 60.degree. C. can be produced very rapidly (over 100 m.sup.3 per hour).
It is a further object of the present invention to provide an apparatus for the use of the method that is not subject to the disadvantages of earlier arrangements.
It is a further object of the present invention to provide an apparatus for the volatilization of a liquid in a gas, this apparatus being of simple design and small dimensions which are well suited for application in modern packaging machines.
These and other objects have been achieved with an apparatus comprising a chamber with feed and discharge lines for the gas and a nozzle for the liquid. The chamber is provided with an internal, helical guide rail, the outlet opening of the nozzle being along the geometric center axis of the helical shape of the guide rail.
The apparatus, because of the helical guide rail and the special orientation of the nozzle relatively to the conical center opening of the guide rails, has proved to function very well and to have a high production capacity. The arrangement is without movable parts and is very simple in its design which entails low manufacturing and operating costs.